Recent advances in fuel delivery and combustion research have allowed direct injection, or DI, fuel delivery systems to increase in popularity. The DI fuel delivery system provides a fuel injector within a cylinder head of an internal combustion engine. The fuel injector operates to inject a predetermined amount of fuel directly into the combustion chamber. The DI fuel delivery system enables higher power levels, improved fuel economy, and lower emissions. These beneficial aspects of the DI fuel delivery system are a result of the precise metering of the fuel injected into the combustion chamber as well as improved intake airflow into the combustion chamber.
Since the fuel injector assembly is in direct communication with the combustion chamber, the fuel injector is subject to high pressure loads and temperatures of the combustion process. Therefore, the fuel injector must be sealed with respect to the cylinder head to prevent combustion gases from leaking past the fuel injector.